We studied the cationic ring-opening polymerization of 2-phenyl-2-oxazoline under microwave irradiation. A comparison with thermal heating shows a great enhancement in the reaction rates while the living character of the polymerization is conserved. The polymerizations were performed at the temperature of boiling butyronitrile (123degrees). The polymerization of 2-phenyl-2-oxazoline under microwave conditions, described herein for the first time, is shown to be a rapid and environmentally friendly alternative to the classical methods.